The Tekunin first appeared in the Game Boy Advance title Mortal Kombat: Tournament Edition, which revolves around the same story as Mortal Kombat: Deadly Alliance. The group is comprised of cybernetic ninja shown to be serving Sektor. The meaning of the clan's name could refer to "iron ninja" or "tech ninja". "Tek" or "teku" may stand for to "tekko", which means "iron" or the slang for tech, and "nin" could be used as short for ninja.
Yes. Most of the arenas have them and they are actually called "death traps."